JP6815090B2 - Display panel and its manufacturing method - Google Patents

Description

The present disclosure relates to a display panel including an organic light emitting element such as an organic light emitting diode (OLED).

As a display panel, one using an organic light emitting diode is known. In such a display panel, a substrate, a lower electrode arranged with a gap in the X-axis direction and the Y-axis direction, an organic light emitting layer provided on each lower electrode, and an upper electrode are laminated in this order. It is composed. The display panel includes a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a sealing layer, and the like, if necessary. A row bank extending in the Y-axis direction may be provided in the gap between the lower electrodes adjacent to each other in the X-axis direction. Further, the organic light emitting layers adjacent to each other in the X-axis direction have different emission colors, and for example, a red organic light emitting layer, a green organic light emitting layer, and a blue organic light emitting layer are arranged in this order in the X axis direction (Patent Document 1). In Patent Document 1, a solution containing an organic luminescent material having a different luminescent color is discharged by an inkjet method into adjacent regions separated by row banks on a substrate, and the solution held in the regions separated by row banks is described. It is described that an organic light emitting layer is formed by drying. The discharge of the solution is performed on the assumption that the solution containing the organic light emitting material is landed at the center of the region divided by the row bank in the X-axis direction (Patent Document 2). Patent Document 2 describes that this solution is held in a region separated by a row bank with its upper surface raised in a convex shape.

Japanese Unexamined Patent Publication No. 2001-291584 Japanese Unexamined Patent Publication No. 2013-187000

It is desired that the display panel improve the device performance by solving the following problems.
First, there is a problem of display failure due to color mixing. In the process of forming the organic light emitting layer, even if it is assumed that the solution is landed in the center of the region divided by the row banks in the X-axis direction, the actual landing position of the solution is one of the row banks that divides this region. It may shift to the side unintentionally. In this case, the entire solution is biased toward one row bank, and the solution may run on this row bank significantly. If a large amount of solution runs on one of the row banks, the solutions containing organic light emitting materials having different emission colors may come into contact with each other on the row bank, and the solutions may be mixed with each other to cause color mixing. In addition, when three RGB color pixels are formed by the inkjet method at the same time, when droplets of different emission colors that should land on the adjacent region are displaced and land on the solution on the row bank, the colors are mixed. May occur. As described above, the color mixing occurs when the solutions are mixed with each other and the solutions contain organic light emitting materials having different light emitting colors. When color mixing occurs, the color of the completed organic light emitting layer becomes poor, causing a problem of display failure on the display panel.

Here, if the width of the column bank is widened in order to suppress the color mixing as described above, there is a problem that the area of the organic light emitting layer (hereinafter, referred to as “aperture ratio”) becomes smaller than the area of the entire display panel. The number of pixels provided on the display panel is defined by the standard, and it is necessary to secure the number of pixels. Therefore, if the width of the column bank is widened to suppress color mixing, the area delimited by the column bank The width becomes narrower. When the width of the region separated by the row bank becomes narrow, the area of the organic light emitting layer becomes small, which causes a problem that the aperture ratio becomes small.

There is also a problem that the film thickness of the organic light emitting layer varies. A certain amount of solution is discharged to the area separated by the row bank according to the design film thickness of the organic light emitting layer, but the amount of solution applied per unit area varies due to unintentional variation in this discharge amount. Sometimes. If the amount of the solution applied per unit area varies, there arises a problem that the film thickness of the organic light emitting layer varies.
Then, there is a problem that it becomes difficult to secure the film thickness of the organic light emitting layer. As the number of pixels per unit area increases for higher image quality, the miniaturization of each subpixel progresses, and the area delimited by the bank becomes narrower. The narrower the area separated by the bank, the more likely it is that the solution applied to that area will swell and overflow. Therefore, the solution cannot be applied in a large amount, the height of the liquid surface after application becomes low, and the amount of solution that can be applied per unit area decreases. As a result, the film thickness of the organic light emitting layer obtained after the solution is dried becomes thin, and it becomes difficult to secure the film thickness.

In this way, the display panel is further improved in device performance such as suppression of display defects due to color mixing, suppression of decrease in aperture ratio, suppression of variation in film thickness of organic light emitting layer, and securing of film thickness of organic light emitting layer. It has been demanded.
An object of the present disclosure is to provide a display panel with improved device performance.

In order to solve the above problems, the display panel according to one aspect of the present disclosure includes a substrate and first, second, and third lower electrodes arranged in order on the substrate with a gap in the first direction. A first row bank arranged in the gap between the first and second lower electrodes and extending in the second direction intersecting the first direction on the substrate, and the second row bank on the substrate. , The first, second, and third banks arranged in the gap between the third lower electrodes and extending in the second direction and above the first, second, and third lower electrodes, respectively. The first organic light emitting layer includes the first, second and third organic light emitting layers and the upper electrodes arranged above the first and second row banks, and the first organic light emitting layer is the first organic light emitting layer. The second organic light emitting layer contains a second organic light emitting material having the same emission color as the first organic light emitting material, and the third organic light emitting layer has the same emission color as the first organic light emitting material. The first ink containing the first organic light emitting material for forming the first organic light emitting layer is applied above the first lower electrode, and the second organic light emitting material is contained. A second ink containing the second organic light emitting material for forming the layer is applied above the second lower electrode, and the third organic light emitting material containing the third organic light emitting material for forming the third organic light emitting layer is formed. When the 3 inks are applied above the 3rd lower electrode, the 2nd row bank has an ink separating ability for the 1st row bank to separate the 1st ink and the 2nd ink. It is lower than the ink separation ability for separating the second ink and the third ink, and the ink separation ability is the height of the first and second row banks, or the said in the first and second row banks. It is characterized by being based on the liquid repellency against the first, second and third inks.

Further, in the method for manufacturing a display panel according to another aspect of the present disclosure, a step of preparing a substrate and first, second, and third lower electrodes are provided on the substrate in order with a gap in the first direction. A step of arranging, a step of forming a first row bank in the gap between the first and second lower electrodes, and a step of forming a second row bank in the gap of the second and third lower electrodes, and a step of forming the first lower electrode. A first ink containing the first organic light emitting material is applied above the above, a second ink containing the second organic light emitting material is applied above the second lower electrode, and above the third lower electrode. The step of applying the third ink containing the third organic light emitting material, the step of drying the first, second, and third inks to form the first, second, and third organic light emitting layers, respectively, and the above. The step of forming the upper electrode so as to cover the upper part of the first, second and third organic light emitting layers and the first and second row banks is included, and the emission color of the second organic light emitting material is the first. It is the same as the emission color of the organic light emitting material, and the emission color of the third organic light emitting material is different from the emission color of the first organic light emitting material.

In the display panel, the ink separation ability of the first row bank is lower than the ink separation ability of the second row bank.
In other words, when the first, second, and third inks are applied, the second and third inks are placed in the second row bank rather than the possibility that the first and second inks run on the first row bank. It is less likely to get on. In other words, the possibility of contact between the second and third inks is lower than the possibility of contact between the first and second inks. Here, since the second organic light emitting material contained in the second ink and the third organic light emitting material contained in the third ink have different emission colors, color mixing occurs when they come into contact with each other. On the other hand, since the first organic light emitting material contained in the first ink and the second organic light emitting material contained in the second ink have the same light emitting color, no color mixing occurs even if they come into contact with each other. As a result, it is possible to suppress the occurrence of color mixing in the entire display panel.

Further, even if the coating amounts of the first ink and the second ink arranged on both sides of the first row bank are unintentionally varied, the applied first ink and the second ink run on the first row bank. Since it is easy to come into contact with each other, it is possible to suppress variations in the film thickness of the first and second organic light emitting layers after completion.
The ink separation ability is based on the height of the first row bank and the second row bank, or the liquid repellency of the first row bank and the second row bank with respect to the first, second, and third inks.

As a result, the ink separation ability can be enhanced without widening the width of the first and second row banks, so that the occurrence of color mixing and the variation in film thickness can be suppressed without lowering the aperture ratio.
Further, in the method of manufacturing the display panel, since the emission colors of the first organic light emitting material contained in the first ink and the second organic light emitting material contained in the second ink are the same, the first ink and the second ink are used. When applying by the inkjet method, even if the landing position of the ink droplets shifts, the occurrence of color mixing can be suppressed.

Therefore, it is possible to provide a display panel with improved device performance.

It is a layout figure of the organic light emitting element in the display panel which concerns on Embodiment 1 of this disclosure. It is a schematic cross-sectional view along the X-axis direction of the display panel of FIG. It is a partially cutaway perspective view which shows the shape of the column bank and the row bank of the display panel of FIG. It is a figure for demonstrating the manufacturing method of the display panel of FIG. 1, (a) shows a partially cutaway perspective view of the process of forming a bank material film on a hole injection layer, (b) is a row bank. A partially cutaway perspective view of the process of forming the above is shown. It is a figure for demonstrating the manufacturing method of the display panel of FIG. 1, (a) shows the partial cut-out perspective view of the process of forming a bank material film on a hole injection layer and a row bank, (b). Shows a partially cutaway perspective view of the process of forming a row bank. It is a figure for demonstrating the manufacturing method of the display panel of FIG. 1, (a) shows the cross-sectional view immediately after applying ink, and (b) shows the cross-sectional view in the state where the ink is in contact on the 1st row bank. (C) shows a cross-sectional view after forming the organic light emitting layer. It is a figure for demonstrating the manufacturing method of the display panel which concerns on a comparative example, (a) shows the cross-sectional view immediately after applying ink, and (b) shows the cross-sectional view after forming an organic light emitting layer. It is a figure for demonstrating the aperture ratio of a display panel, (a) shows the sectional view of the display panel of FIG. 1, and (b) shows the sectional view of the display panel which concerns on comparative example. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on Embodiment 2 of this disclosure. It is a partially cutaway perspective view which shows the shape of the column bank and the row bank of the display panel of FIG. 9 is a view for explaining the manufacturing method of the display panel of FIG. 9, where FIG. 9A shows a cross-sectional view of a state in which ink is in contact on the first row bank, and FIG. 9B is a cross-sectional view after forming the organic light emitting layer. Is shown. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on Embodiment 3 of this disclosure. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on Embodiment 4 of this disclosure. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on the modification 1 of this disclosure. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on the modification 2 of this disclosure. It is a layout figure of the lower electrode and the organic light emitting layer in the display panel which concerns on the modification 3 of this disclosure. It is a partially cutaway perspective view which shows the shape of the column bank and the row bank of the display panel of FIG. It is a layout figure of the lower electrode and the organic light emitting layer in the display panel which concerns on the modification 4 of this disclosure. It is a partially cutaway perspective view which shows the shape of the column bank and the row bank of the display panel of FIG. It is a schematic cross-sectional view along the X-axis direction of the display panel which concerns on modification 5. FIG.

<< Outline of one aspect of the present disclosure >>
The display panel according to one aspect of the present disclosure includes a substrate, first, second, and third lower electrodes arranged in order on the substrate with a gap in the first direction, and on the substrate. A first row bank arranged in the gap between the first and second lower electrodes and extending in the second direction intersecting the first direction, and a gap between the second and third lower electrodes on the substrate. The first, second, and third organic light emitting layers arranged above the first, second, and third lower electrodes, respectively, and the first row bank extending in the second direction. A second and third organic light emitting layer and an upper electrode arranged above the first and second row banks, the first organic light emitting layer contains a first organic light emitting material and the second organic light emitting material. The light emitting layer contains a second organic light emitting material having the same emission color as the first organic light emitting material, and the third organic light emitting layer contains a third organic light emitting material having a different emission color from the first organic light emitting material. The first ink containing the first organic light emitting material for forming the first organic light emitting layer is applied above the first lower electrode to form the second organic light emitting layer. The second ink containing the two organic light emitting materials is applied above the second lower electrode, and the third ink containing the third organic light emitting material for forming the third organic light emitting layer is the third lower portion. When applied above the electrodes, the first row bank has the ink separation ability to separate the first ink from the second ink, and the second row bank has the second ink and the third ink. It is lower than the ink separation ability for separating ink, and the ink separation ability is the height of the first and second row banks, or the first, second, and third rows of the first and second row banks. It shall be based on the liquid repellency against ink.

According to the display panel according to one aspect of the present disclosure, the display panel has a lower ink separation ability of the first row bank than that of the second row bank.
In other words, when the first, second, and third inks are applied, the second and third inks are placed in the second row bank rather than the possibility that the first and second inks run on the first row bank. It is less likely to get on. In other words, the possibility of contact between the second and third inks is lower than the possibility of contact between the first and second inks. Here, since the second organic light emitting material contained in the second ink and the third organic light emitting material contained in the third ink have different emission colors, color mixing occurs when they come into contact with each other. On the other hand, since the first organic light emitting material contained in the first ink and the second organic light emitting material contained in the second ink have the same light emitting color, no color mixing occurs even if they come into contact with each other. As a result, it is possible to suppress the occurrence of color mixing in the entire display panel.

Further, even if the coating amounts of the first ink and the second ink arranged on both sides of the first row bank are unintentionally varied, the applied first ink and the second ink run on the first row bank. Since it is easy to come into contact with each other, it is possible to suppress variations in the film thickness of the first and second organic light emitting layers after completion.
The ink separation ability is based on the height of the first row bank and the second row bank, or the liquid repellency of the first row bank and the second row bank with respect to the first, second, and third inks.

As a result, the ink separation ability can be adjusted without widening the width of the first and second row banks, so that the occurrence of color mixing and the variation in film thickness can be suppressed without lowering the aperture ratio.
In a specific aspect of the display panel according to one aspect of the present disclosure, the ink separation ability is based on the height of the first and second row banks, and the height of the first row bank is the height of the second row. It may be lower than the height of the bank.

Since the height of the first row bank is lower than the height of the second row bank, the first ink and the second ink applied to both sides of the first row bank easily ride on the first row bank and come into contact with each other. In other words, the first row bank has a lower ink separation ability than the second row bank. In this way, by changing the height of the row banks, the ink separation ability can be changed without widening the bank width, so that the occurrence of color mixing and the variation in film thickness can be suppressed without lowering the aperture ratio. Can be done.

In a specific aspect of the display panel according to one aspect of the present disclosure, the ink separating ability is based on the liquid repellency of the first and second row banks to the first, second and third inks. The liquid repellency of the first row bank with respect to the first ink and the second ink may be lower than the liquid repellency of the second bank with respect to the second ink and the third ink.
Since the liquid repellency of the first row bank is lower than that of the second row bank, the first ink and the second ink applied to both sides of the first row bank ride on the first row bank and come into contact with each other. It's easy to do. In other words, the first row bank has a lower ink separation ability than the second row bank. In this way, by changing the liquid repellency of the row banks, the ink separation ability can be changed without widening the bank width, so that the occurrence of color mixing and the variation in film thickness are suppressed without lowering the aperture ratio. be able to.

In a specific aspect of the display panel according to one aspect of the present disclosure, the first organic light emitting layer and the second organic light emitting layer may each ride on the first row bank and come into contact with each other.
This indicates that when the first ink and the second ink are applied, the first ink and the second ink run on the first row bank and come into contact with each other, thereby causing the first organic light emission. It is possible to suppress variations in the devil's cave of the layer and the second organic light emitting layer.

In a specific aspect of the display panel according to one aspect of the present disclosure, the thickness of the first and second organic light emitting layers may be thicker than the thickness of the third organic light emitting layer.
As a result, the film thickness of the first and second organic light emitting layers can be secured.
In a specific aspect of the display panel according to one aspect of the present disclosure, at least one of the first, second, and third organic light emitting layers may have different widths in the first direction.

Thereby, the width in the first direction can be adjusted based on the brightness of the organic light emitting layer and the like.
In a specific aspect of the display panel according to one aspect of the present disclosure, among the first, second, and third organic light emitting layers, the one having the shortest luminance half life has the largest width in the first direction. You may.

As a result, it is possible to increase the area of the organic light emitting layer, which has a short luminance half life and tends to decrease the luminance relatively early, and suppress the occurrence of luminance unevenness.
In a specific aspect of the display panel according to one aspect of the present disclosure, among the first, second, and third organic light emitting layers, the one having the longest luminance half life has the smallest width in the first direction. You may.

As a result, it is possible to reduce the area of the organic light emitting layer, which has a long half-luminance life and is relatively difficult to reduce the luminance, and suppress the occurrence of uneven luminance.
In the method for manufacturing a display panel according to another aspect of the present disclosure, a step of preparing a substrate and first, second, and third lower electrodes are arranged on the substrate with a gap in order in the first direction. A step of forming a first row bank in the gap between the first and second lower electrodes and a second row bank in the gap between the second and third lower electrodes, and a step above the first lower electrode. A first ink containing the first organic light emitting material is applied thereto, a second ink containing the second organic light emitting material is applied above the second lower electrode, and a third ink containing the second organic light emitting material is applied above the third lower electrode. A step of applying a third ink containing an organic light emitting material, a step of drying the first, second, and third inks to form first, second, and third organic light emitting layers, respectively, and the first step. , A step of forming an upper electrode so as to cover the upper part of the second and third organic light emitting layers and the first and second row banks, and the emission color of the second organic light emitting material is the first organic. It is the same as the light emitting color of the light emitting material, and the light emitting color of the third organic light emitting material is different from the light emitting color of the first organic light emitting material.

As a result, the emission colors of the first organic light emitting material contained in the first ink and the second organic light emitting material contained in the second ink are the same, so that when the first ink and the second ink are applied by the inkjet method, they are used. Even if the landing position of the ink droplets shifts, the occurrence of color mixing can be suppressed.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, in the step of applying the first, second, and third inks, the applied first ink and the second ink are used. However, the first ink and the second ink may be applied so as to ride on the first row bank and come into contact with each other.

Since the emission colors of the first ink and the second ink are the same, no color mixing occurs even if the first ink and the second ink come into contact with each other. Therefore, even if the coating amounts of the first ink and the second ink are unintentionally varied, the variation in the film thickness of the first organic light emitting layer and the second organic light emitting layer is suppressed without causing color mixing. can do.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the height of the first row bank may be lower than the height of the second row bank.

Since the height of the first row bank is lower than the height of the second row bank, the first ink and the second ink applied to both sides of the first row bank easily ride on the first row bank and come into contact with each other. In other words, the first row bank has a lower ink separation ability than the second row bank. In this way, by changing the height of the row banks, the ink separation ability can be changed without widening the bank width, so that the occurrence of color mixing and the variation in film thickness can be suppressed without lowering the aperture ratio. Can be done.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the liquid repellency of the first row bank to the first ink and the second ink is the second of the second bank. It may be lower than the liquid repellency to the ink and the third ink.
Since the liquid repellency of the first row bank is lower than that of the second row bank, the first ink and the second ink applied to both sides of the first row bank ride on the first row bank and come into contact with each other. It's easy to do. In other words, the first row bank has a lower ink separation ability than the second row bank. In this way, by changing the liquid repellency of the row banks, the ink separation ability can be changed without widening the bank width, so that the occurrence of color mixing and the variation in film thickness are suppressed without lowering the aperture ratio. be able to.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the width of the first row bank in the first direction may be narrower than the width of the second row bank.
The aperture ratio can be improved by narrowing the width of the first row bank. Further, since the width of the first row bank is narrower than the width of the second row bank, the first ink and the second ink applied to both sides of the first row bank easily ride on the first row bank and come into contact with each other. .. In other words, the first row bank has a lower ink separation ability than the second row bank. In this way, the ink separation ability can be changed by changing the width of the row bank, and the occurrence of color mixing and the variation in film thickness can be suppressed.

Further, in recent years, each subpixel has been miniaturized in order to improve the image quality. As the subpixels become finer, the area separated by the bank becomes narrower, and the applied solution tends to overflow even if it rises a little, so that the solution cannot be raised and applied. When the height of the liquid surface after coating is low, the amount of solution that can be coated per unit area decreases, and the film thickness of the organic light emitting layer obtained after solution drying becomes thin, making it difficult to secure the film thickness. Become.

On the other hand, in a specific aspect of the method for manufacturing the display panel, the width of the first row bank is narrower than that of the second row bank, so that the solution for forming the first, second, and third organic light emitting layers is provided. The area to be applied can be increased, and the solution can be raised and applied. As a result, the amount of solution that can be applied per unit area can be increased.
Further, since the width of the first row bank is narrower than the width of the second row bank, the solutions applied to both sides of the first row bank easily run on the first row bank and come into contact with each other. Here, in a specific aspect of the method for manufacturing the display panel, the first ink containing the first organic light emitting material coated on one side of the first row bank and the second organic light emitting material coated on the other side are included. Since the second inks have the same emission color, no color mixing occurs even if they come into contact with each other. Therefore, when the inks on both sides ride on the first row bank and come into contact with each other, the ink can be applied in a larger area over the area of two subpixels, so that the ink can be applied per unit area. The amount of ink can be further increased.

As a result, it becomes easy to secure the film thickness of the first, second, and third organic light emitting layers even when the subpixels are miniaturized.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the volume applied per unit area of the third ink is applied per unit area of the first and second inks. It may be less than the volume.

As a result, even if the subpixels are miniaturized, the film thickness of the organic light emitting layer can be secured by increasing the volume per unit area of the ink containing the organic light emitting material.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the viscosity of the third ink may be higher than the viscosity of the first and second inks.
When the application amount of the ink containing the organic light emitting material is the same, the lower the viscosity of the ink, the greater the degree of riding on the row bank. When an ink having a relatively high viscosity is used as the third ink, the degree of the third ink that rides on the second row bank is small, so that it is difficult to come into contact with the adjacent second ink, and the occurrence of color mixing can be suppressed.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the steps of applying the first, second, and third inks are performed from the first, second, and third inks from the inkjet device. The length of the ligament of the third ink may be shorter than the length of the ligament of the first and second inks.
The longer the ligament, the easier it is for the ink droplets containing the organic luminescent material to land unintentionally. When an ink having a relatively short ligament is used for the third ink, the landing position of the third ink droplet is relatively difficult to shift, so that the third ink droplet gets over the second row bank and is hard to come into contact with the second ink. , The occurrence of color mixing can be suppressed.

Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. In the following drawings, the first direction will be described as the X-axis direction and the second direction will be described as the Y-axis direction.
<< Embodiment 1 >>
1. 1. Configuration of display panel 1 <Layout of organic light emitting element>
FIG. 1 shows the layout of the organic light emitting element in the display panel 1.

The display panel 1 has a display area 1a for displaying an image. In the display area 1a, for example, a red organic light emitting element 10R that emits red light (R), a green organic light emitting element 10G that emits green light (G), and a blue organic light emitting element 10B that emits blue light (B). Are arranged in the X-axis direction and the Y-axis direction. The red organic light emitting element 10R, the green organic light emitting element 10G, and the blue organic light emitting element 10B (hereinafter, referred to as "organic light emitting element 10" when no distinction is necessary) are arranged corresponding to the subpixels. There is. The shape of each organic light emitting element 10 is, for example, a rectangular shape.

A red organic light emitting element 10R, a green organic light emitting element 10G, a blue organic light emitting element 10B, a blue organic light emitting element 10B, a green organic light emitting element 10G, and a red organic light emitting element 10R are repeatedly arranged in the positive direction of the X axis. Further, the red organic light emitting element 10R, the green organic light emitting element 10G, and the blue organic light emitting element 10B adjacent to each other in the X-axis direction constitute one pixel 10P. For example, when the display panel 1 is a full high-definition standard, 1920 pixels in the X-axis direction and 1080 pixels in the Y-axis direction are arranged in a matrix on the display panel 1. The emission colors of the organic light emitting elements 10 adjacent to each other in the Y-axis direction are the same.

<Cross-sectional structure of display panel 1>
Next, the cross-sectional structure of the display panel 1 will be described with reference to the schematic cross-sectional view of FIG. The figure is a cross-sectional view of the display panel 1 of FIG. 1, and mainly shows two pixels adjacent to each other in the X-axis direction.
The display panel 1 includes a substrate 11, first, second, and third lower electrodes 12a, 12b, and 12c (hereinafter, referred to as "lower electrode 12" when it is not necessary to distinguish them), and a hole injection layer 13. , The hole transport layer 14, the red organic light emitting layer 15R, the green organic light emitting layer 15G, and the blue organic light emitting layer 15B (hereinafter, referred to as "organic light emitting layer 15" when there is no need to distinguish), and the electron transport layer. 16, the electron injection layer 17, the upper electrode 18, the sealing layer 19, the first row bank 31, the second row bank 32, and the third row bank 33 (hereinafter, when there is no need to distinguish, “ It is referred to as a column bank 30 ”). Further, although not shown in this cross-sectional view, the display panel 1 also includes a row bank 40. The organic light emitting element 10 is composed of each layer from the lower electrode 12 to the upper electrode 18. In the present embodiment, the display panel 1 is a top-emission type display panel, and light is emitted upward in the Z-axis direction in the figure. Hereinafter, each component of the display panel 1 will be described.

2. 2. Each component of display panel 1 <board>
The substrate 11 is configured by, for example, laminating a TFT layer and an interlayer insulating layer in this order on a glass substrate. As the material of the glass substrate, for example, soda lime glass, non-alkali glass and the like can be used. The TFT layer includes a plurality of transistor element portions in each subpixel. Each transistor element unit includes three electrodes of a gate, a source, and a drain, a semiconductor layer, and a passivation film. As the material of the interlayer insulating layer, for example, polyimide, polyamide, acrylic resin and the like can be used.

<Lower electrode>
The lower electrode 12 is electrically connected to the TFT layer on the substrate 11 and functions as an anode. The lower electrode 12 is arranged with a gap in the X-axis direction and a gap in the Y-axis direction. The first lower electrode 12a, the second lower electrode 12b, and the third lower electrode 12c are repeatedly arranged in the X-axis direction. The shape of each lower electrode 12 is rectangular. The end of the lower electrode 12 in the X-axis direction is covered with a row bank 30.

The width of the lower electrode 12 is uniform. Hereinafter, in the present specification, the term "width" refers to a dimension in the X-axis direction. The width W21 of the gap 21 of the first and second lower electrodes 12a and 12b adjacent to each other in the X-axis direction, the width W22 of the gap 22 of the second and third lower electrodes 12b and 12c adjacent to each other in the X-axis direction, in the X-axis direction. The width W23 of the gap 23 of the adjacent first and third lower electrodes 12a and 12c is the same. The dimensions of the gaps between the lower electrodes 12 adjacent to each other in the Y-axis direction in the Y-axis direction are uniform. The widths W12a1 and W12b1 of the portions of the lower electrode 12 covered by the first row banks 31 are the widths W12b2 and W12c2 of the portions of the lower electrodes 12 covered by the second and third row banks 32 and 33, respectively. , W12c3, narrower than W12a1. Therefore, the width W31 of the first row bank 31 is narrower than the widths W32 and W33 of the second and third row banks 32 and 33. The width of the portion of the lower electrode 12 that is not covered by the row bank 30 corresponds to the width of the organic light emitting element 10. The end of the lower electrode 12 in the Y-axis direction is also covered with the row bank 40.

As the material of the lower electrode 12, a metal material containing silver (Ag) or aluminum (Al) can be used. Since the display panel 1 is a top emission type, the surface of the lower electrode 12 preferably has high light reflectivity. The thickness of the lower electrode 12 is, for example, 100 nm or more and 1000 nm or less.
<Hole injection layer>
The hole injection layer 13 is arranged on the lower electrode 12 and in a portion corresponding to the gap between the adjacent lower electrodes 12 on the substrate 11. The hole injection layer 13 has a function of improving the hole injection property from the lower electrode 12 into the organic light emitting layer 15. As the material of the hole injection layer 13, an inorganic material such as a metal oxide can be used. As the metal oxide, for example, metal oxides such as silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), and iridium (Ir) are used. be able to. The thickness of the hole injection layer 13 is, for example, 5 nm or more and 100 nm or less.

<Hall transport layer>
The hole transport layer 14 is arranged on the hole injection layer 13. The hole transport layer 14 has a function of transporting holes injected from the lower electrode 12 to the organic light emitting layer 15. The material of the hole transport layer 14 is an organic material. As the organic material, for example, polyfluorene or a derivative thereof, or a polymer compound such as polyarylamine or a derivative thereof can be used. The thickness of the hole transport layer 14 is, for example, 5 nm or more and 50 nm or less.

<Organic light emitting layer>
The organic light emitting layer 15 is arranged on the hole transport layer 14. Each organic light emitting layer 15 is separated by a row bank 30. Although not shown, the organic light emitting layers 15 adjacent to each other in the Y-axis direction ride on the row bank 40 and are in contact with each other. The organic light emitting layer 15 has a function of generating excitons and emitting light by injecting holes and electrons and recombining them. The red organic light emitting layer 15R contains a red organic light emitting material. Similarly, the green organic light emitting layer 15G contains a green organic light emitting material, and the blue organic light emitting layer 15B contains a blue organic light emitting material. As the organic light emitting material, high molecular weight organic materials such as polyfluorene, polyphenylene vinylene, polyacetylene, polyphenylene, and polyparaphenylene ethylene can be used. The thickness of the red organic light emitting layer 15R and the blue organic light emitting layer 15B is thicker than the thickness of the green organic light emitting layer 15G. The thickness of the organic light emitting layer 15 is, for example, 30 nm or more and 200 nm or less.

<Electron transport layer>
The electron transport layer 16 is arranged on the entire surface of the organic light emitting layer 15, the column bank 30, and the row bank 40. The electron transport layer 16 has a function of transporting the electrons injected from the upper electrode 18 to the organic light emitting layer 15. As the material of the electron transport layer 16, for example, an oxadiazole derivative (OXD), a triazole derivative (TAZ), a phenanthroline derivative (BCP, Bphen) and the like can be used. The thickness of the electron transport layer 16 is, for example, 5 nm or more and 50 nm or less.

<Electron injection layer>
The electron injection layer 17 is arranged on the electron transport layer 16. The electron injection layer 17 has a function of improving the electron injection property from the upper electrode 18 to the organic light emitting layer 15. As the material of the electron injection layer, for example, a metal complex containing an alkali metal can be used. The thickness of the electron injection layer 17 is, for example, 5 nm or more and 50 nm or less.

<Upper electrode>
The upper electrode 18 is arranged above the row bank 30 and on the electron transport layer 16. Further, although not shown, the upper electrode 18 is also arranged on the row bank 40. The upper electrode 18 functions as a negative electrode. As the material of the upper electrode 18, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or the like can be used. Since the display panel 1 is a top emission type, the material of the upper electrode 18 is preferably a light transmissive material. The thickness of the upper electrode 18 is, for example, 50 nm or more and 500 nm or less.

<Encapsulation layer>
The sealing layer 19 is arranged on the upper electrode 18. The sealing layer 19 has a function of suppressing exposure of each layer from the lower electrode 12 to the upper electrode 18 to moisture or air. As the material of the sealing layer 19, for example, SiN (silicon nitride) or the like can be used.
<Bank>
The row bank 30 is arranged on the hole injection layer 13 and covers the gap between the lower electrodes 12 adjacent to each other in the X-axis direction and the end portion of the lower electrode 12 as described above. The height of the row bank 30 is uniform, for example, 1 μm or more and 2 μm or less. Here, the height of the row bank 30 refers to "the height from the upper surface of the substrate 11 to the upper surface of the row bank 30". The height of the row bank 40 also refers to "the height from the upper surface of the substrate 11 to the upper surface of the row bank 40". All of the row banks 30 have liquid repellency. As the material of the row bank 30, a photoresist containing fluorine or the like can be used. Examples of the photoresist containing fluorine include a material containing PFOA (ammonium perfluorooctanoate).

The width W31 of the first row bank 31 is narrower than the width W32 of the second row bank 32 and the width of the third row bank 33. The width W31 of the first row bank 31 is, for example, 5 μm or more and 15 μm or less, and the width W32 of the second row bank 32 and the width of the third row bank 33 are, for example, 10 μm or more and 30 μm or less. The width W31 of the first row bank 31 is about 50% of the width W32 of the second row bank 32 and the width of the third row bank 33.

As shown in FIG. 3, the row bank 40 is arranged on the hole injection layer 13 and covers the gap between the lower electrodes 12 adjacent to each other in the Y-axis direction and the end portion of the lower electrode 12 as described above. There is. In the figure, for convenience, the layers above the column bank 30 and the row bank 40 are removed. A plurality of sets of the first, second, and third lower electrodes 12a, 12b, and 12c are arranged with a gap in the Y-axis direction, and the first, second, and third lower electrodes 12a, which are adjacent to each other in the Y-axis direction. The row banks 40 are arranged in the gaps between the pairs of 12b and 12c. The height of the row banks 40 is set to such a height that the organic light emitting material ink applied to the regions between the row banks 40 adjacent to each other in the Y-axis direction comes into contact with each other when the organic light emitting layer described later is formed. The height of the row bank 40 is, for example, 0.3 μm or more and 1 μm or less. The row bank 40 has a relatively low liquid repellency. As the material of the row bank 40, a hydrophilic photoresist can be used. In addition to this, an inorganic material may be used as the material of the row bank 40. Examples of the inorganic material include silicon oxide, silicon nitride, and silicon oxynitride.

3. 3. Manufacturing Method of Display Panel 1 This embodiment is characterized by the structure of a column bank. Hereinafter, the manufacturing method of the display panel 1 and particularly the process of forming the row bank and the column bank will be mainly described with reference to the partially cutaway perspective views of FIGS. 4 to 6.
As shown in FIG. 4A, the hole injection layer 13 is formed on the substrate 11 on which the lower electrode 12 is formed, and then the bank material film 40R is formed on the entire surface of the hole injection layer 13. The substrate 11 has a TFT layer and an interlayer insulating layer formed on the upper surface of a glass substrate, and is manufactured by a known technique. The lower electrode 12 is formed by forming a metal film on the substrate 11 using a sputtering method or a vacuum vapor deposition method, and then patterning the metal film. Further, the hole injection layer 13 is formed by forming a metal oxide film on the substrate 11 on which the lower electrode 12 is formed by using a sputtering method or a vacuum vapor deposition method. The bank material film 40R is formed by applying a hydrophilic photoresist in a liquid state using a coating method such as a spin coating method.

Next, as shown in FIG. 4B, a row bank 40 is formed. The row bank 40 is formed by patterning the bank material film 40R by exposure and development and firing it. Specifically, in the exposure, UV irradiation treatment is performed via a mask to cure a part of the bank material film 40R. In development, the uncured portion of the bank material film is removed with a developer.
As shown in FIG. 5A, the bank material film 30R is formed on the entire surface of the hole injection layer 13 on which the row bank 40 is formed. Similar to the bank material film 40R, the bank material film 30R is formed by applying a photoresist containing fluorine in a liquid state by using a coating method such as a spin coating method.

Further, as shown in FIG. 5B, the column bank 30 is formed. The row bank 30 is formed by patterning the bank material film 30R by exposure and development and firing it. Specifically, in the exposure, UV irradiation treatment is performed via a mask to cure a part of the bank material film 30R. In development, the uncured portion of the bank material film is removed with a developer.

As described above, in the step of forming the row bank 30, the first, second, and third row banks 31, 32, and 33 are simultaneously formed in the same step.
4. Effect Next, the effect of the column bank 30 will be described with reference to FIGS. 6 to 8. In the display panel 1, the width of the first row bank is narrower than the width of the second and third row banks, and in the display panel 901 according to the comparative example, the width of the first row bank is the same as the width of the second and third row banks. The display panels 1 and 901 differ in that they are present. 6 and 7 are cross-sectional views showing a step of forming the organic light emitting layer 15, and FIG. 8 is a cross-sectional view of the display panel 1 according to the present embodiment and the display panel 901 according to a comparative example. 6 and 8 (a) show the display panel 1 according to the present embodiment, and FIGS. 7 and 8 (b) show the display panel 901.

(First effect of column bank 30)
In both the display panels 1 and 901, the film thickness of the red organic light emitting layer and the blue organic light emitting layer is thicker than the film thickness of the green organic light emitting layer. Therefore, the display panels 1 and 901 agree that the coating amount of the red organic light emitting material ink and the blue organic light emitting material ink per unit area is larger than the coating amount of the green organic light emitting material ink per unit area. There is. In addition, the display panels 1 and 901 are also in agreement that the amount of the blue organic light emitting material ink, which should be originally uniform, varies unintentionally. On the other hand, in the display panel 1, the width of the first row bank is narrower than the width of the second and third row banks, and in the display panel 901, the width of the first row bank is the width of the second and third row banks. The display panels 1 and 901 are different in that they are the same.

The formation of the organic light emitting layer 15 of the display panel according to the comparative example will be described with reference to FIG. Hereinafter, when it is not necessary to distinguish between the first, second, and third row banks 931, 932, and 933, they are referred to as "row bank 930". As shown in FIG. 7 (a), on the substrate 11 on which the lower electrode 12, the hole injection layer 13, and the hole transport layer 14 are formed, in the region separated by the row banks 930 adjacent to each other in the X-axis direction. Apply ink containing organic luminescent material. Specifically, the blue organic light emitting material ink 15BI or the red organic light emitting material ink 15RI is discharged to the region separated by the first and second row banks 931 and 932, and the second and third row banks 932 and 933 The green organic light emitting material ink 15GI is discharged to the divided region, and the blue organic light emitting material ink 15BI or the red organic light emitting material ink 15RI is discharged to the region divided by the first and third row banks 931 and 933. When it is not necessary to distinguish between the red organic light emitting material ink 15RI, the green organic light emitting material ink 15GI, and the blue organic light emitting material ink 15BI, it is referred to as "organic light emitting material ink 15I". The discharged organic light emitting material ink 15I has a shape in which the upper surface is raised in a convex shape, and is held in a region separated by the row bank 930 with both ends riding on the row bank 930. The width of the portion of the organic light emitting material ink 15I that rides on the row bank 930 becomes wider as the amount of the organic light emitting material ink 15I applied increases. In the display panel 901, since all of the row banks 930 are wide, the adjacent organic light emitting material inks 15I do not come into contact with each other on the row banks. In addition, the amount of the blue organic light emitting material ink 15BI, which should be originally uniform, varies unintentionally. Therefore, when the organic light emitting material ink 15I is dried, the thickness of the completed blue organic light emitting layer 15B varies as shown in FIG. 7B.

Next, the formation of the organic light emitting layer 15 of the display panel 1 will be described with reference to FIG. As shown in FIG. 6A, the blue organic light emitting material ink 15BI or the red organic light emitting material ink 15RI is ejected into the regions separated by the banks 31 and 32 in the first and second rows, and the second and third rows The green organic light emitting material ink 15GI is discharged to the region separated by the banks 32 and 33, and the blue organic light emitting material ink 15BI or the red organic light emitting material ink 15RI is discharged to the region separated by the first and third rows banks 31 and 33. Discharge. The coating amount of the blue organic light emitting material ink 15BI, which should be originally uniform, varies unintentionally. On the other hand, the width of the first row bank 31 is narrower than the width of the second and third row banks 32 and 33. Further, blue organic light emitting material inks 15BI having the same light emitting color are adjacent to each other, and these inks are separated by a first row bank 31. Therefore, the adjacent blue organic light emitting material ink 15BI and the adjacent red organic light emitting material ink 15RI ride on the first row bank 31 and come into contact with each other.

The blue organic light emitting material ink 15BI and the red organic light emitting material ink 15RI that are in contact with each other form one ink pool as shown in FIG. 6 (b). Therefore, even if the coating amount of the blue organic light emitting material ink 15BI varies, the volume of the blue organic light emitting material remaining in each region surrounded by the row banks 30 can be leveled. As a result, as shown in FIG. 6C, it is possible to suppress variations in the film thickness of the blue organic light emitting layer 15B after completion.

(Second effect of column bank 30)
As shown in FIG. 6B, one ink pool formed by the contacted blue organic light emitting material ink 15BI has a higher ink pool height than the case where the ink pool is divided into the first row banks 31. The same applies to the red organic light emitting material ink 15RI. As described above, in the display panel 1, the volume of the blue organic light emitting material ink 15BI per unit area can be increased. Therefore, even if the subpixels are miniaturized, the film thickness of the organic light emitting layer can be secured by increasing the volume per unit area of the organic light emitting material ink.

(Third effect of column bank 30)
As shown in FIG. 6A, since the widths of the second and third row banks 32 and 33 are wider than the width of the first row banks 31, the adjacent red organic light emitting material ink 15RI and green organic light emitting It is possible to prevent the material ink 15GI, the adjacent blue organic light emitting material ink 15BI, and the green organic light emitting material ink 15GI from coming into contact with each other on the second and third row banks 32 and 33. That is, the color mixing of the organic light emitting material ink 15I can be suppressed.

(Fourth effect of column bank 30)
As shown in FIG. 8B, in the display panel 901, the width W931 of the first row bank 931 is the same as the widths W932 and W933 of the second and third row banks 932 and 933. As shown in FIG. 8A, in the display panel 1, the width W931 of the first row bank 31 is narrower than the widths W32 and W33 of the second and third row banks 32 and 33. Therefore, the area occupied by the column bank 30 in the display panel 1 is smaller than the area occupied by the column bank 930 in the display panel 901.

As described above, since the width of the organic light emitting element 10 corresponds to the width of the portion of the lower electrode 12 that is not covered with the row bank 30, the width of the organic light emitting element depends on the width of the row bank and the width of the pixel. It is decided. Therefore, the width of the organic light emitting elements 10R, 10G, and 10B in the display panel 1 can be wider than the width of the organic light emitting elements 910R, 910G, and 910B in the display panel 901. That is, the display panel 1 can have an aperture ratio higher than that of the display panel 901.

<< Embodiment 2 >>
The second embodiment will be described with reference to FIGS. 9 to 11. The basic configuration of the display panel 101 of the second embodiment shown in the cross-sectional view of FIG. 9 is substantially the same as that of the first embodiment. In the second embodiment, the height of the first row bank is lower than the height of the second and third row banks, and the widths of the first, second, and third row banks are the same. Is different from. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

1. 1. Configuration of Display Panel 101 In the display panel 101, the widths W131, W32, of the first, second, and third row banks 131, 32, 33 (hereinafter, referred to as "column bank 130" when there is no need to distinguish). W33 is the same. On the other hand, the height H131 of the first row bank 131 is lower than the height H32 of the second and third row banks. Therefore, in the display panel 101, the hole transport layers 14 adjacent to each other in the X-axis direction ride on the first row bank 131 and are in contact with each other. Further, the blue organic light emitting layer 15B adjacent to the X-axis direction rides on and contacts the first row bank 131, and the red organic light emitting layer 15R adjacent to the X-axis direction also rides on and contacts the first row bank 131.

The height of the first row bank 131 is, for example, 0.5 μm or more and 1 μm or less, and the height of the second and third row banks is, for example, 1 μm or more and 2 μm or less. The height H131 of the first row bank 131 is, for example, 60% or less of the height H32 of the second row bank 32 and the third row bank 33.
FIG. 10 is a partially cutaway perspective view showing the column bank 130 and the row bank 40, and is shown by removing the layers above the column bank 130 and the row bank 40 for convenience. In the present embodiment, the height of the first column bank 131 and the height of the row bank 40 are the same.

2. 2. Effect FIG. 11 is a cross-sectional view showing a step of forming the organic light emitting layer 15 in the display panel 101. FIG. 11A is a cross-sectional view showing a state in which the organic light emitting material ink 15I is applied to the region surrounded by the adjacent row banks 30. Since the height of the first row bank 131 is lower than the height of the second and third row banks 32 and 33, the blue organic light emitting material ink 15BI comes into contact with each other on the first row bank 131 and becomes one ink pool. Become. Similarly, the red organic light emitting material ink 15RI also contacts on the first row bank 131 to form one ink sump. Then, the organic light emitting material ink 15I is dried to form the organic light emitting layer 15 as shown in FIG. 11 (b). In the display panel 101, the blue organic light emitting material ink 15BI becomes one ink sump on the first row bank 131, and the red organic light emitting material ink 15RI also becomes one ink sump on the first row bank 131, so that the blue organic light emitting material emits blue light. Variations in the thickness of the layer 15B and the red organic light emitting layer 15R can be suppressed.

Further, the height of the second and third row banks 32 is higher than the height of the first row bank 131. Therefore, the adjacent red organic light emitting material ink 15RI and the green organic light emitting material ink 15GI, the adjacent blue organic light emitting material ink 15BI and the green organic light emitting material ink 15GI come into contact with each other on the second and third row banks 32 and 33. Can be suppressed. That is, the color mixing of the organic light emitting material ink 15I can be suppressed.

<< Embodiment 3 >>
The third embodiment will be described with reference to FIG. The basic configuration of the display panel 201 of the third embodiment shown in the cross-sectional view of FIG. 12 is substantially the same as that of the first embodiment. In the third embodiment, the heights of the first, second, and third row banks are the same, the widths of the first, second, and third row banks are the same, and the liquid repellency of the first row banks is , It differs from the first embodiment in that it is lower than the liquid repellency of the second and third row banks. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

1. 1. Configuration of Display Panel 201 In the display panel 201, the widths W231, W32, of the first, second, and third column banks 231 and 32, 33 (hereinafter, referred to as "column bank 230" when there is no need to distinguish). W33 is the same. The heights of the first, second and third row banks 231, 32 and 33 are the same. On the other hand, the liquid repellency of the first row bank 231 is lower than the liquid repellency of the second and third row banks 32 and 33. Therefore, in the display panel 201, the hole transport layer 14 and the blue organic light emitting layer 15B ride on the first row bank 231 and are in contact with each other. Similarly, the hole transport layer 14 and the red organic light emitting layer 15R ride on the first row bank 231 and are in contact with each other.

When forming the column bank 230 and the row bank, the row bank 40 is formed, then the first column bank 231 is formed, and finally, the second and third column banks 32 and 33 are simultaneously formed in the same process. It may be formed.
The column bank 230 and the row bank 40 may be formed by other manufacturing methods. The method for manufacturing the column bank 230 and the row bank 40 is selected in consideration of "material", "liquid repellency", and "height".

In order to impart liquid repellency to the row bank 230, in addition to using a photoresist containing fluorine as the material, the row bank may be formed of an organic material containing no fluorine and the row bank may be surface-treated. Good. As the surface treatment, after exposing and developing the organic material, the surface is plasma-treated with fluorine gas through a mask in which only the region to be imparted liquid repellency is opened, and then the mask is removed to repel the surface. It suffices to have liquidity.

In addition to forming column banks 230 and row banks 40 having different heights in different steps, a halftone mask having a partially different light transmittance is used when patterning after applying an organic material. By using it, the heights of the column banks and row banks to be formed may be different. By using the halftone mask, column banks and row banks having different heights can be formed at the same time in the same process.

Hereinafter, a modified example of the manufacturing method of the column bank 230 and the row bank 40 will be specifically described. When the column bank 230 and the row bank 40 are made of an organic material, after the row bank 40 is formed, the first column bank 231 and the second and third column bank material layers are made of a fluorine-free organic material in the same step. The second and third row banks may be formed at the same time, and the second and third row bank material layers may be further imparted with liquid repellency by surface treatment to form the second and third row banks. In addition, a row bank and a column bank material layer are simultaneously formed in the same process using a halftone mask with a fluorine-free organic material, and further, liquid repellency is imparted by surface treatment to give the second and third layers. A column bank may be formed.

When the first column bank 231 and the row bank 40 are made of an inorganic material and the liquid-repellent second and third column banks are made of an organic material, the first column bank 231 and the row bank 40 are simultaneously formed in the same process. It may be formed, and then the second and third row banks may be formed with a photoresist containing fluorine. Further, after forming the first column bank 231 and the row bank 40 at the same time in the same step, the second and third column bank material layers are formed of an organic material containing no fluorine, and further, the liquid repellency is improved by surface treatment. It may be added to form a second and third row bank.

The column banks and row banks having configurations other than the third embodiment can also be manufactured by various methods as in the third embodiment.
2. 2. Effect Since the liquid repellency of the first row bank 231 is lower than the liquid repellency of the second and third row banks 32 and 33, the blue organic light emitting material ink 15BI is used in the first row in the step of forming the organic light emitting layer 15. One ink pool is formed on the bank 231 and the red organic light emitting material ink 15RI is also one ink pool on the first row bank 231. Therefore, variations in film thickness of the blue organic light emitting layer 15B and the red organic light emitting layer 15R can be suppressed.

Further, since the second and third row banks 32 and 33 have liquid repellency, adjacent red organic light emitting material ink 15RI and green organic light emitting material ink 15GI, adjacent blue organic light emitting material ink 15BI and green organic light emitting material ink It is possible to prevent the 15GI from coming into contact with the second and third row banks 32 and 33. That is, the color mixing of the organic light emitting material ink 15I can be suppressed.
<< Embodiment 4 >>
The fourth embodiment will be described with reference to FIG. The basic configuration of the display panel 301 of the fourth embodiment shown in the cross-sectional view of FIG. 13 is substantially the same as that of the first embodiment. In the fourth embodiment, the height of the first row bank is lower than the height of the second and third row banks, the width of the first row bank is narrower than the width of the second and third row banks, and the first row. The liquid repellency of the bank is different from that of the first embodiment in that it is lower than the liquid repellency of the second and third row banks. That is, the fourth embodiment has all the characteristics of the first row bank in the first, second, and third embodiments. The same components as those of the first, second, and third embodiments are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

1. 1. Configuration of Display Panel 301 In the display panel 301, the height H331 of the first row bank 331 is lower than the height H33 of the second and third row banks 32 and 33. Further, the width W331 of the first row bank 331 is narrower than the widths W32 and W33 of the second and third row banks 32 and 33. In addition, the liquid repellency of the first row banks 331 is lower than the liquid repellency of the second and third row banks 32 and 33.

When forming the column bank 330 and the row bank 40, the row bank 40 may be formed, then the first column bank 331 may be formed, and finally the second and third column banks 32 and 33 may be formed. ..
2. 2. Effect Also in this configuration, in the step of forming the organic light emitting layer 15, the blue organic light emitting material ink 15BI becomes one ink sump on the first row bank 331, and the red organic light emitting material ink 15RI also forms on the first row bank 331. It becomes one ink pool. Compared with the first row banks of the first, second, and third embodiments, the organic light emitting material ink easily gets over the first row bank 331, so that the organic light emitting material inks having the same emission color are more easily contacted. Therefore, as compared with the first, second, and third embodiments, the variation in film thickness of the blue organic light emitting layer 15B and the red organic light emitting layer 15R can be further suppressed.

Further, the adjacent red organic light emitting material ink 15RI and the green organic light emitting material ink 15GI, the adjacent blue organic light emitting material ink 15BI and the green organic light emitting material ink 15GI come into contact with each other on the second and third row banks 32 and 33. Can be suppressed. That is, the color mixing of the organic light emitting material ink 15I can be suppressed.
<< Modification example >>
Hereinafter, a modified example will be described.

1. 1. Modification 1
Modification 1 will be described with reference to FIG. The basic configuration of the display panel 401 of the modification 1 shown in the cross-sectional view of FIG. 14 is substantially the same as that of the first embodiment. The first modification is different from the first embodiment in that the width of the lower electrode is non-uniform and the width of the portion of the lower electrode exposed from the row bank is also non-uniform. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In the display panel 401, the widths W12a and W12b of the first and second lower electrodes 12a and 12b are narrower than the width W12c of the third lower electrode 12c. The width of the portion of the first and second lower electrodes 12a and 12b exposed from the row bank 30 is wider than the width of the portion of the third lower electrode 12c exposed from the row bank 30. The width of the portion of the first and second lower electrodes 12a and 12b exposed from the row bank 30 corresponds to the widths W410B and W410R of the blue organic light emitting element 410B and the red organic light emitting element 410R, respectively. The width of the portion of the third lower electrode 12c exposed from the row bank 30 corresponds to the width W410G of the green organic light emitting element 410G. In this way, the opening width of the display panel 401 can be made different for each emission color of the organic light emitting layer 15. Therefore, the overall luminance half life of the display panel 401 can be improved by widening the aperture width of the organic light emitting layer 15 having a short luminance half life and narrowing the aperture width of the organic light emitting layer 15 having a long luminance half lifetime. The "luminance half-life" referred to here means the time required for applying a predetermined drive current to the organic light emitting layer 15 and halving the brightness.

2. 2. Modification 2
Modification 2 will be described with reference to FIG. The basic configuration of the display panel 501 of the modification 2 shown in the cross-sectional view of FIG. 15 is substantially the same as that of the fourth embodiment. The second modification is different from the fourth embodiment in that the emission colors of the organic light emitting layer are red, green, blue, and white. The same components as those in the fourth embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In the display panel 501, the width W531 of the first row bank 531 is narrower than the widths W32, W33, W34 of the second, third, and fourth row banks 32, 33, 34. The height H531 of the first row bank 531 is lower than the height H32 of the second, third, and fourth row banks 32, 33, and 34. A white organic light emitting layer 15W is arranged between the adjacent third and fourth row banks 33 and 34. In this way, the emission colors of the organic light emitting layer on the display panel 501 can be four colors. As a result, the display panel 501 can emit light with higher brightness even if the drive voltage is the same, as compared with the case where the emission colors of the organic light emitting element are three colors.

3. 3. Modification 3
In the above-described embodiment, the height of the row banks is such that when the organic light emitting layer is formed, the organic light emitting material ink applied to the region between the row banks adjacent to each other in the Y-axis direction comes into contact with each other and after completion. The height was such that the organic light emitting layer climbed onto the row bank and came into contact with each other. However, not limited to this, the height of the row banks is such that when the organic light emitting layer is formed, the organic light emitting material ink applied to the region between the adjacent row banks in the Y-axis direction comes into contact with the organic light emitting material ink after completion. The height may be such that the light emitting layer is separated by a row bank. Further, a row bank having a high height and a row bank having a low height may be provided. Such a modification will be described below with reference to FIGS. 16 to 19.

The display panel 601 shown in the layout diagram of FIG. 16 differs from the first embodiment in that one organic light emitting layer is provided above the four lower electrodes or above the lower electrodes arranged in two rows. .. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
FIG. 16 is a layout diagram of the lower electrode and the organic light emitting layer in the display panel 601. A line-shaped blue organic light emitting layer 15B is arranged above the first lower electrode 12a arranged in a row in the Y-axis direction and the second lower electrode 12b adjacent to the first lower electrode 12a in the Y-axis direction and arranged in the Y-axis direction. ing. A square red organic light emitting layer 15R and a green organic light emitting layer 15G are arranged above the two third lower electrodes 12c adjacent to each other in the Y-axis direction and the fourth lower electrode 12d adjacent to each other in the X-axis direction. ..

FIG. 17 shows the first, second column banks 631, 632 (hereinafter referred to as “column bank 630” when no distinction is necessary), and the first, second, and third row banks 641 in the display panel 601. It is a partially cutaway perspective view showing 642 and 643 (hereinafter, referred to as "row bank 640" when it is not necessary to distinguish them), and for convenience, the layers above the column bank 30 and the row bank 640 are removed and shown. is there.

The width of the first row bank 631 is narrower than the width of the second row bank 632. The height of the first row bank 631 is lower than the height of the second row bank 632. The liquid repellency of the first row bank 631 is lower than the liquid repellency of the second row bank 632. The heights of the first and second row banks 641 and 642 are lower than the height of the third row bank 643 and are the same as the height of the first column bank 631. The liquid repellency of the first and second bank banks 641 and 642 is lower than the liquid repellency of the third row bank 643. Therefore, when the column bank 630 and the row bank 640 are formed on the display panel 601, the first column bank 631 and the first and second row banks 641 and 642 are simultaneously formed in the same process, and the second column bank is formed. The 632 and the third row bank 643 may be formed at the same time in the same process.

4. Modification 4
The display panel 701 shown in the layout diagram of FIG. 18 is a display panel according to the fourth modification, in which one organic light emitting layer is provided above the four lower electrodes, and the light emitting colors of the organic light emitting layer are red and green. It differs from the first embodiment in that it is blue and white. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

FIG. 18 is a layout diagram of the lower electrode and the organic light emitting layer in the display panel 701. A square blue organic light emitting layer 15B and a white organic light emitting layer 15W are arranged above the two first lower electrodes 12a adjacent to each other in the Y-axis direction and the second lower electrode 12b adjacent to each other in the X-axis direction. .. A square red organic light emitting layer 15R and a green organic light emitting layer 15G are arranged above the two third lower electrodes 12c adjacent to each other in the Y-axis direction and the fourth lower electrode 12d adjacent to each other in the X-axis direction. ..

FIG. 19 shows the first and second column banks 731 and 732 (hereinafter referred to as “column bank 730” when no distinction is necessary) and the first and second row banks 741 and 742 (hereinafter referred to as “column bank 730”) in the display panel 701. It is a partially cutaway perspective view showing (referred to as “row bank 740” when there is no need to distinguish between them), and for convenience, the layers above the column bank 730 and the row bank 740 are removed.

The width of the first row bank 731 is narrower than the width of the second row bank 732. The height of the first row bank 731 is lower than the height of the second row bank 732. The liquid repellency of the first row bank 731 is lower than the liquid repellency of the second row bank 732. The height of the first row bank 741 is lower than the height of the second row bank 742 and is the same as the height of the first column bank 731. The liquid repellency of the first row bank 741 is lower than the liquid repellency of the second row bank 742. Therefore, when the column bank 730 and the row bank 740 are formed on the display panel 701, the first column bank 731 and the first row bank 741 are formed at the same time in the same process, and the second column bank 732 and the second row are formed. Banks 742 may be formed simultaneously in the same process.

In this way, the display panel can be designed more freely by providing the row banks having different heights.
5. Modification 5
In the first embodiment, as shown in FIG. 2, the width of the gap between the lower electrodes 12 adjacent to each other in the X-axis direction is the same, and the lower electrodes 12 are covered by the first row bank 31. The configuration in which the widths W12a1 and W12b1 of the portions are narrower than the widths W12b2, W12c2, W12c3 and W12a1 of the portions covered by the second and third row banks 32 and 33, respectively, has been described. However, the present invention is not limited to this, and the following modifications can be made.

FIG. 20 is a schematic cross-sectional view of the display panel 801 according to the modified example 5. The same components as those of the display panel 1 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
The basic configuration of the display panel 801 is substantially the same as the configuration of the display panel 1. In the display panel 801, the widths of the portions of the lower electrodes covered by the first row bank, the second row bank, and the third row bank are the same, and the first lower electrode 12a and the second lower electrode 12b have the same width. The width W822 of the gap 22 between the second lower electrode 12b and the third lower electrode 12c and the gap 23 between the third lower electrode 12c and the first lower electrode 12a are larger than the width W21 of the gap 21 between the two. It differs from the display panel 1 according to the first embodiment in that the width W823 is large.

Also by the configuration of this modification, the width W31 of the first row bank 31 can be made narrower than the width W32 of the second row bank 32 and the width W33 of the third row bank 33, which is the same as that of the first embodiment. The effect can be obtained.
6. Other modifications (selection of third organic light emitting layer)
In the above embodiments, the organic light emitting layer having the thinnest film thickness is selected as the third organic light emitting layer, but the present invention is not limited to this, and the "viscosity of the organic light emitting material ink" and "organic light emitting material at the time of ejection" are not limited to this. It can be selected in consideration of "the length of the ink ligament" and "the method of forming the organic light emitting material ink". The term "ligament" as used herein refers to the case where a droplet of an organic light emitting material ink in a state from being ejected to landing is composed of a spherical portion and a tail portion. Say the part. Hereinafter, these contents will be described.

As the third organic light emitting layer, in the step of forming the organic light emitting layer, the organic light emitting layer formed by the ink having a relatively high viscosity is selected from the organic light emitting material inks applied to the regions between the adjacent row banks. You may. When the organic light emitting material ink is held in the region between the adjacent row banks, when the coating amount of the organic light emitting material ink is the same, the organic light emitting material ink having a lower viscosity has a larger width to ride on the row bank. When an ink having a relatively high viscosity is used for the third organic light emitting layer, the width of the ink that rides on the row bank is small, so that the occurrence of color mixing can be suppressed.

Further, as the third organic light emitting layer, in the step of forming the organic light emitting layer, the organic light emitting material ink applied to the region between the adjacent row banks is formed by the ink having a relatively short ligament length. An organic light emitting layer may be selected. When ejecting the organic light emitting material ink into the region between adjacent row banks, the longer the ligament, the more easily the landing position of the organic light emitting material ink is unintentionally displaced. By providing the second row bank between the organic light emitting material ink having a relatively long ligament and another organic light emitting material ink, it is possible to suppress the contact of these inks and prevent the occurrence of color mixing.

Further, as the third organic light emitting layer, in the step of forming the organic light emitting layer, an organic light emitting layer formed by depositing a low molecular weight organic light emitting material instead of applying ink may be selected. In the organic light emitting layer formed by thin film deposition, uneven film thickness does not occur due to variations in the amount of ink applied. By providing the first row bank between the adjacent first and second organic light emitting layers, which may cause uneven film thickness due to the variation in the coating amount of the ink, the first and second organic light emitting material inks are brought into contact with each other. Variations in the film thickness of the first and second organic light emitting layers can be suppressed.

(Contact and non-contact of the first and second organic light emitting layers)
In the first embodiment, when the organic light emitting layer is formed, the first and second organic light emitting material inks applied to the regions between the row banks adjacent to each other in the first direction are in contact with each other. The first and second organic light emitting layers were separated by a first row bank. However, not limited to this, when the liquid repellency of the first, second, and third row banks is low to some extent, the completed first and second organic light emitting layers ride on the first row bank and come into contact with each other. Sometimes.

(Characteristics of the first row bank)
In the above embodiments, the first row bank is said to be "narrower than the second row bank", "lower than the second row bank", and "has relatively low liquid repellency". It had one or all of the features. However, the present invention is not limited to this, and two of these three features may be provided.

(Other)
A plurality of configurations may be freely combined in the configurations such as the above-described embodiment.
The present disclosure may also be summarized as follows.
The display panel according to one aspect of the present disclosure includes a substrate and first, second, and third subpixel regions arranged in order on the substrate along a first direction parallel to the upper surface of the substrate with a gap. And, on the substrate, the first row bank arranged in the gap of the first and second subpixel regions and extending in the second direction intersecting with the first direction, and on the substrate, the said The second row bank arranged in the gap between the second and third subpixel regions and extending in the second direction, and the first, second, and second banks arranged in the first, second, and third subpixel regions, respectively. The first organic light emitting layer includes the first organic light emitting material, and the second organic light emitting layer is a second organic light emitting material having the same emission color as the first organic light emitting material. The third organic light emitting layer contains a third organic light emitting material whose emission color is different from that of the first organic light emitting material.

In a specific aspect of the display panel according to one aspect of the present disclosure, a first ink containing the first organic material for forming the first organic light emitting layer is applied to the first subpixel region, and the first ink is applied. A second ink containing the second organic material for forming the second organic light emitting layer is applied to the second subpixel region and contains the third organic material for forming the third organic light emitting layer. When the third ink is applied to the third subpixel region, the first row bank has an ink separation ability to separate the first ink from the second ink. It may be lower than the ink separation ability for separating the second ink and the third ink.

In a particular aspect of the display panel according to one aspect of the present disclosure, the ink separating ability relates to the width of the first and second row banks in the first direction, and the width of the first row bank is said to be said. It may be narrower than the width of the second row bank.
In a specific aspect of the display panel according to one aspect of the present disclosure, the ink separating ability relates to the liquid repellency of the first and second row banks to the first, second and third inks. The liquid repellency of the row bank to the first ink and the second ink may be lower than the liquid repellency of the second bank to the second ink and the third ink.

In a specific aspect of the display panel according to one aspect of the present disclosure, the ink separability is the height of the first and second row banks, and the height of the first row bank is the height of the second row bank. It may be lower than the height of.
In a specific aspect of the display panel according to one aspect of the present disclosure, the first organic light emitting layer and the second organic light emitting layer may each ride on the first row bank and come into contact with each other.

In a specific aspect of the display panel according to one aspect of the present disclosure, the thickness of the first and second organic light emitting layers may be thicker than the thickness of the third organic light emitting layer.
In a specific aspect of the display panel according to one aspect of the present disclosure, at least one of the first, second, and third organic light emitting layers may have different widths in the first direction.
In a specific aspect of the display panel according to one aspect of the present disclosure, among the first, second, and third organic light emitting layers, the one having the shortest luminance half life has the largest width in the first direction. You may.

In a specific aspect of the display panel according to one aspect of the present disclosure, among the first, second, and third organic light emitting layers, the one having the longest luminance half life has the smallest width in the first direction. You may.
A method for manufacturing a display panel according to another aspect of the present disclosure includes a step of preparing a substrate and a gap on the substrate along a first direction parallel to the upper surface of the substrate. The step of forming the first and second row banks extending in the intersecting second direction in order, and the first organic emission in the first subpixel region adjacent to the first row bank on the opposite side of the second row bank. The first ink containing the material is applied, and the second ink containing the second organic light emitting material is applied to the second subpixel region, which is the region between the first row bank and the second row bank, and the second ink is applied. The step of applying the third ink containing the third organic light emitting material to the third subpixel region adjacent to the second row bank on the side opposite to the first row bank, and the first, second, and third inks are applied. The step of forming the first, second, and third organic light emitting layers by drying is included, and the light emitting color of the second organic light emitting material is the same as the light emitting color of the first organic light emitting material. The emission color of the third organic light emitting material may be different from the emission color of the first organic light emitting material.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the width of the first row bank in the first direction may be narrower than the width of the second row bank.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the liquid repellency of the first row bank to the first ink and the second ink is the second of the second bank. It may be lower than the liquid repellency to the ink and the third ink.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the height of the first row bank may be lower than the height of the second row bank.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the volume applied per unit area of the third ink is applied per unit area of the first and second inks. It may be less than the volume.

In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the viscosity of the third ink may be higher than the viscosity of the first and second inks.
In a specific aspect of the display panel manufacturing method according to another aspect of the present disclosure, the steps of applying the first, second, and third inks are performed from the first, second, and third inks from the inkjet device. Is done by discharging
The length of the ligament of the third ink may be shorter than the length of the ligament of the first and second inks.

The present disclosure is useful for displays and the like of various electronic devices.

1 Display panel 10R, 10G, 10B Red organic light emitting element, green organic light emitting element, blue organic light emitting element 11 Substrate 11a, 11b, 11c 1st lower electrode, 2nd lower electrode, 3rd lower electrode 13 holes Injection layer 14 holes Transport Layers 15R, 15G, 15B Red organic light emitting layer, green organic light emitting layer, B light emitting layer 15RI, 15GI, 15BI Red organic light emitting material ink, green organic light emitting material ink, blue organic light emitting material ink 16 electron transport layer 17 electron injection layer 18 Upper electrode 19 Sealing layer 21, 22, 23 Gap 31, 32, 33 1st column bank, 2nd column bank, 3rd column bank 40 row bank

Claims (14)

With the board
The first, second, and first, second, which are arranged on the substrate in order corresponding to the first, second, and third subpixel regions with a gap in the first direction, and the drive voltage is individually applied at the time of driving. With the third lower electrode
A first row bank on the substrate, arranged in the gap between the first and second lower electrodes, and extending in the second direction intersecting the first direction.
On the substrate, the second row bank arranged in the gap between the second and third lower electrodes and extending in the second direction, and
The first, second, and third organic light emitting layers arranged above the first, second, and third lower electrodes, respectively,
It is provided with the first, second and third organic light emitting layers and an upper electrode arranged above the first and second row banks.
The first organic light emitting layer contains the first organic light emitting material and contains.
The second organic light emitting layer contains a second organic light emitting material having the same emission color as the first organic light emitting material.
The third organic light emitting layer contains a third organic light emitting material whose emission color is different from that of the first organic light emitting material.
The first ink containing the first organic light emitting material for forming the first organic light emitting layer is applied above the first lower electrode, and the second organic for forming the second organic light emitting layer. A second ink containing a light emitting material is applied above the second lower electrode, and a third ink containing the third organic light emitting material for forming the third organic light emitting layer is a third ink containing the third organic light emitting material of the third lower electrode. When applied upward, the first row bank separates the first ink from the second ink, and the second row bank has the second ink and the third ink. Is lower than the ink separation ability to separate
The ink separation ability is based on the height of the first and second row banks, and the height of the first row bank is lower than the height of the second row bank . With the board
The first, second, and first, second, which are arranged on the substrate in order corresponding to the first, second, and third subpixel regions with a gap in the first direction, and the drive voltage is individually applied at the time of driving. With the third lower electrode
A first row bank on the substrate, arranged in the gap between the first and second lower electrodes, and extending in the second direction intersecting the first direction.
On the substrate, the second row bank arranged in the gap between the second and third lower electrodes and extending in the second direction, and
The first, second, and third organic light emitting layers arranged above the first, second, and third lower electrodes, respectively,
It is provided with the first, second and third organic light emitting layers and an upper electrode arranged above the first and second row banks.
The first organic light emitting layer contains the first organic light emitting material and contains.
The second organic light emitting layer contains a second organic light emitting material having the same emission color as the first organic light emitting material.
The third organic light emitting layer contains a third organic light emitting material whose emission color is different from that of the first organic light emitting material.
The first ink containing the first organic light emitting material for forming the first organic light emitting layer is applied above the first lower electrode, and the second organic for forming the second organic light emitting layer. A second ink containing a light emitting material is applied above the second lower electrode, and a third ink containing the third organic light emitting material for forming the third organic light emitting layer is a third ink containing the third organic light emitting material of the third lower electrode. When applied upward, the first row bank separates the first ink from the second ink, and the second row bank has the second ink and the third ink. Is lower than the ink separation ability to separate
The ink separation ability is based on the liquid repellency of the first and second row banks for the first, second and third inks, and the liquid repellency for the first ink and the second ink of the first row bank. A display panel having a property lower than the liquid repellency of the second bank for the second ink and the third ink . The display panel according to claim 1 or 2 , wherein the first organic light emitting layer and the second organic light emitting layer respectively ride on the first row bank and are in contact with each other. The display panel according to any one of claims 1 to 3 , wherein the thickness of the first and second organic light emitting layers is thicker than the thickness of the third organic light emitting layer. The display panel according to any one of claims 1 to 4 , wherein at least one of the first, second, and third organic light emitting layers has a different width in the first direction. The display panel according to claim 5 , wherein among the first, second, and third organic light emitting layers, the one having the shortest luminance half life is the one having the widest width in the first direction. The display panel according to claim 5 , wherein among the first, second, and third organic light emitting layers, the one having the longest luminance half life is the one having the smallest width in the first direction. The process of preparing the board and
The first, second, and first, second, which are arranged on the substrate in order corresponding to the first, second, and third subpixel regions with a gap in the first direction, and the drive voltage is individually applied at the time of driving. The process of arranging the third lower electrode and
A step of forming a first row bank in the gap between the first and second lower electrodes and forming a second row bank in the gap between the second and third lower electrodes.
A first ink containing a first organic light emitting material is applied above the first lower electrode, a second ink containing a second organic light emitting material is applied above the second lower electrode, and the third lower portion is coated. A process of applying a third ink containing a third organic light emitting material above the electrodes, and
The steps of drying the first, second, and third inks to form the first, second, and third organic light emitting layers, respectively.
Including a step of forming an upper electrode so as to cover above the first, second and third organic light emitting layers and the first and second row banks.
The emission color of the second organic light emitting material is the same as the emission color of the first organic light emitting material.
The emission color of the third organic light emitting material is different from the emission color of the first organic light emitting material.
The ink separating ability of the first row bank to separate the first ink and the second ink is larger than the ink separating ability of the second row bank to separate the second ink and the third ink. Low,
The method for manufacturing a display panel, wherein the ink separation ability is based on the height of the first and second row banks, and the height of the first row bank is lower than the height of the second row bank . The process of preparing the board and
The first, second, and first, second, which are arranged on the substrate in order corresponding to the first, second, and third subpixel regions with a gap in the first direction, and the drive voltage is individually applied at the time of driving. The process of arranging the third lower electrode and
A step of forming a first row bank in the gap between the first and second lower electrodes and forming a second row bank in the gap between the second and third lower electrodes.
A first ink containing a first organic light emitting material is applied above the first lower electrode, a second ink containing a second organic light emitting material is applied above the second lower electrode, and the third lower portion is coated. A process of applying a third ink containing a third organic light emitting material above the electrodes, and
The steps of drying the first, second, and third inks to form the first, second, and third organic light emitting layers, respectively.
Including a step of forming an upper electrode so as to cover above the first, second and third organic light emitting layers and the first and second row banks.
The emission color of the second organic light emitting material is the same as the emission color of the first organic light emitting material.
The emission color of the third organic light emitting material is different from the emission color of the first organic light emitting material.
The ink separating ability of the first row bank to separate the first ink and the second ink is larger than the ink separating ability of the second row bank to separate the second ink and the third ink. Low,
The ink separation ability is based on the liquid repellency of the first and second row banks for the first, second and third inks, and the liquid repellency for the first ink and the second ink of the first row bank. A method for manufacturing a display panel whose property is lower than the liquid repellency of the second ink and the third ink of the second bank . In the step of applying the first, second, and third inks, the first ink is applied so that the applied first ink and the second ink ride on the first row bank and come into contact with each other. The method for manufacturing a display panel according to claim 8 or 9 , wherein the second ink is applied. The method for manufacturing a display panel according to any one of claims 8 to 10 , wherein the width of the first row bank in the first direction is narrower than the width of the second row bank. The display panel according to any one of claims 8 to 11 , wherein the volume applied per unit area of the third ink is smaller than the volume applied per unit area of the first and second inks. Production method. The method for manufacturing a display panel according to any one of claims 8 to 12 , wherein the viscosity of the third ink is higher than the viscosity of the first and second inks. The steps of applying the first, second, and third inks are performed by ejecting the first, second, and third inks from the inkjet device.
The method for manufacturing a display panel according to any one of claims 8 to 13 , wherein the length of the ligament of the third ink is shorter than the length of the ligament of the first and second inks.

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